\\[-1.8ex] Soil Heterogeneity & $-$0.220 & 0.274 & 0.215 & 0.306 & 0.227 & 0.220 \\ 
  & (0.369) & (0.365) & (0.361) & (0.358) & (0.356) & (0.356) \\ 
  & & & & & & \\ 
\\[-1.8ex] 
Observations & 570,121 & 570,121 & 570,121 & 570,121 & 566,731 & 566,731 \\ 
R$^{2}$ & 0.012 & 0.013 & 0.013 & 0.014 & 0.014 & 0.014 \\ 
